In the US, the required reserve ratio has been 0% since March 2020. I personally wouldn't view the traditional financial system as about as trustworthy as things get.
The ratio you're talking about is the amount that needs to be in the bank's account with the Federal Reserve as a fraction of its total liabilities. Only the money in that bank account qualifies for that reserve ratio; holding on to a literal stack of dollar bills in a bank vault somewhere does not.
That ratio is 0% because it's been judged that there are better ways to require solvency than doing that (chiefly, requiring capital buffers).
